Many techniques for three-dimensional measurement to be made using projectors and a camera have been proposed (see non-patent literature 1 and 2, for example). According to such techniques, projector light is coded in some way or another; projected light is received by a camera; correspondence is established, making use of coding, between points on the projector images and points on the camera image; and three-dimensional distances are measured based on the theory of triangulation. Three-dimensional information obtained by measurement is presented to users, for example, by displaying the information on a display device (see patent literature 1 and 2) or by presenting the information on a windshield using a head-up display (HUD) (see patent literature 3).